This invention relates to electronic board identification method and apparatus for use in large computer systems with a plurality of module boards.
Main frame computer systems generally include a plurality of computer module boards, including processing modules, memory modules, input/output controllers, and power system boards. It has been a general practice to provide the module boards with a mechanical protrusion specially located on each board so that a board could not be incorrectly inserted into the computer frame. A computer frame has a number of slots for receiving computer module boards each uniquely provided with mating holes for the protrusions of the correctly inserted module board to engage. However, it has been found that this mechanical keying method suffers from the disadvantage of being easily defeated. It is not uncommon for an identifying protrusion to become worn and fall off a module board or computer frame. When a protrusion is lost so is the protection of the keying method. Similarly, technicians encountering a computer module board which is difficult to fit into a slot in the main frame may tend to attempt jamming the module board into the slot. This may further damage the mechanical keying mechanisms and may overcome the protection normally provided. If the mechanical keying is defeated, a module board may end up in an incorrect slot leading to possible damage of the board or the computing system.